The prior art is already aware of many different arrangements of trenching chains with digging members thereon, and isolated examples are found in U.S. Pat. Nos. 2,772,491 and 2,828,557 and 2,888,757. In the prior art, the digging tooth itself is generally arranged so that it loosens the dirt or material in which the trench is being formed, and the material is dragged out of the trench by means of the longitudinal movement of the chain with the digging members thereon. However, the chains of the prior art are not generally arranged for efficient movement of the dirt or like material from the trench, and the prior art is not aware of provision of chains which efficiently loosen the dirt and also remove it from the trench, all in one action or the continuous movement of the chain itself.
Accordingly, it is a primary object of this invention to improve upon trenching chains and to particularly provide a chain which has scoop teeth mounted thereon so that the teeth can both loosen the material and also remove it from the trench, all in one efficient and continuous motion of the chain. That is, the tooth design of this invention is such that it provides a scooping or dragging of the material from the trench, as well as loosening or cutting the material prior to removal from the trench.
Still further, the apparatus for trenching commonly employs a receiving auger which moves the material off to one side and thus permits efficient handling of the material dug out of the trench, and the present invention provides a staggering of the scoop or drag teeth which therefore efficiently distribute the dirt or material along the length of the auger which can therefore more easily and efficiently handle the continuous movement of the dirt to the auger.
Still further, the scoop or drag tooth of this invention is arranged to accomplish the aforementioned objectives and the tooth is formed with one curvature therein and thus is easily formed and fabricated and is of a sturdy construction and of a low cost, and the tooth of this invention can therefore be formed from rolled edge blade stock thus avoiding mill cut and thereby effecting the lower cost.
Still further, another important aspect of this invention is the provision of a trenching chain which has scoop or drag teeth mounted therealong and which has a tooth pick or bar which is mounted on the chain to articulate in a manner different from the articulation of the scoop tooth itself, such as when the chain is going around a sprocket or the like, and thus the tooth pick is provided for clearing the material from the scoop tooth and thus keep the chain free of clogging and capable of operating at full efficiency and capacity and to assure that the cut material will be dropped off the scoop tooth when the chain is moving around a sprocket to thereby create the relative movement between the scoop tooth and the tooth pick, as mentioned.
Still further, the present invention provides a trenching chain with a scoop or drag tooth having a scoop surface faced generally in the longitudinal direction of the chain and mounted on links of the chain but behind the location of the mounting link itself, all for providing an accelerated motion of the scoop tooth surface around the sprocket to flip the dirt out of the tooth.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings: